Supporting means for shutter of oven door window



April 22, 1969 w. K. WINKLER 3,439,669

SUPPORTING MEANS FOR SHUTTER OF OVEN DOOR WINDOW Filed Feb. 1, 1968Sheet of 2 FIGI INVENTOR. NH-LIAM K. W) NKLER BY o Hxs ATTORNEY April22, 1969 w. K. WINKLER 3,439,669

SUPPORTING MEANS FOR SHUTTER OF OVEN DOOR WINDOW v ma Feb.- 1, 1968Sheet 3 of 2 INVENTOR. W\LLIAM K. WlNKLER H vs ATTORN-EY United StatesPatent 3,439,669 SUPPORTING MEANS FOR SHUTTER OF OVEN DOOR WINDOWWilliam K. Winkler, Anchorage, Ky., assignor to General ElectricCompany, a corporation of New York Filed Feb. 1, 1968, Ser. No. 702,221Int. Cl. F24c 15/04 US. Cl. 126-200 4 Claims ABSTRACT OF THE DISCLOSUREThis invention relates to an oven door that has a window sealed withtransparent panes. The door may be used with a high temperature,self-cleaning oven, where it would be necessary to provide the windowwith a shutter to close the window when the oven is operating on aself-cleaning oven cycle. The shutter may be retracted into the doorstructure during normal clocking operations, and raised to a closed'position when the oven is to be operated at a high temperature. Theshutter has handles at the top corners, and the inner surface of thedoor has slots through which the handles extend so the handles areaccessible on the inner side of the door. A gravity actuated catchmember is positioned within the door near the top thereof forautomatically engaging the handle after the door is opened and theshutter is raised to its closed position for supporting the shutter inplace.

Cross-reference to related art This invention is a refinement of thedetent system for supporting the shutter in the windowed oven door ofPatent No. 3,311,106 of Howard B. Baughman and Kermit B. Keeling, Sr.,which issued on Mar. 28, 196 7 and is assigned to General ElectricCompany, assignee of the present invention. Moreover, the particularshutter shown in the present application is described in the pendingpatent application Ser. No. 644,257 of William K. Winkler and Eugene E.Pickerrell entitled Track System for Shutter of Windowed Oven Door whichwas filed on June 7, 1967, now Patent No. 3,396,717 and is likewiseassigned to the assignee of the present invention.

Background of the invention Housewives have become accustomed to theconvenience of a window in their oven door so that they may observe thefood while it is being cooked. This avoids the necessity of opening theoven door in order to judge the degree of doneness of the food. However,in recent years housewives have been given the opportunity of owning aself-cleaning oven that operates on the principal of pyrolysis fordecomposing the food soil and grease splatter that accumulate on theoven walls during normal cooking operations. Such a self-cleaning ovenis taught in the patent of Bohdan Hurko No. 3,121,158 which is likewiseassigned to the assignee of this invention. Such self-cleaning ovensoperate at a high temperature range above the normal cooking temperaturerange of between 150 F. to 550 F., generally above a temperature ofabout 750. The conventional windowed oven doors were not usable inself-cleaning ovens for confining the increased amount of heat energy tothe oven cavity, and hence they were omitted in the early models ofselfcleaning ovens in order to take full advantage of the self-cleaningoven feature. The above-cited Baughman et a1. Patent 3,311,106 teachesthe use of a movable shutter built into the door structure so that inone position the shutter blocks the window opening and serves as both athermal radiation barrier and a visual barrier during the hightemperature operation. During normal 3,439,669 Patented Apr. 22, 1969"ice cooking operations this shutter will be retracted into the doorstructure so that the window will provide the convenience of the ovendoor windows in standard ovens. The shutter of the present invention isdesigned to be supported in its raised position by a gravity actuatedcatch member where no spring devices are involved, where the expansionof the shutter when exposed to high temperature does not effect theholding force of the catch, and whereby no force applied to the shuttercan override the catch and permit the shutter to be lowered during thehigh temperature self-cleaning operation.

Summary of the invention The present invention, in accordance with oneform thereof, relates to a door construction for a high temperature ovenwhere the door includes a window opening that is closed by a pluralityof transparent panes that are sealed along their periphery to the doorstructure. A manually movable shutter is located within the door, and inone position the shutter blocks the window opening and in a secondposition the shutter is retracted into the door structure. Track meansin the door support and guide the shutter. The shutter includes handlesat the top corners thereof, and the inner door panel is provided withslots so that the handles may extend outwardly therethrough and beaccessible on the inner side of the door. A catch member is positionedin the door near the top thereof for automatically engaging a handleafter the door is opened and the shutter is raised to its closedposition for supporting the shutter in place.

Brief description of the drawings My invention will be better understoodfrom the following description taken in conjunction with theaccompanying drawings and its scope 'will be pointed out in the appendedclaims.

FIGURE 1 is a side elevational view of a free-standing range with aself-cleaning oven having a windowed oven door embodying the presentinvention with parts broken away and others in cross-section to show themain ele ments of the oven as well as to show the appearance of theinner surface of the door with the handles of the shutter extending outthrough vertical slots in the inner door panel as well as the releasemeans for the catch member so that the shutter may be lowered whendesired.

FIGURE 2 is a fragmentary plan view on an enlarged scale through the topleft corner of the range of FIGURE 1 taken on the lines 22 thereofshowing the three panes of high temperature transparent glass which aresealed over the window openings in the inner and outer door panels, aswell as the shutter sandwiched between the first and second innermostpanes, and having an outwardly extending handle which extends outthrough a slot in the inner door panel torender the handle accessible sothat the shutter may be engaged and raised and lowered when necessary.This view also shows a pivoted catch member which is capable of engagingthe handle after the door is opened and the shutter is raised to itstopmost position.

FIGURE 3 is a front elevational view taken on the lines 33 of FIGURE 2with the front half of the door removed to expose the shutter andillustrate the manner of supporting and guiding the shutter on a tracksystem. The view also shows a mechanical interlock system which isoperated by the shutter in its raised position and cooperates with anoven door latching mechanism to insure that the oven door may not belatched unless the shutter is supported in its raised position blockingthe Window opening.

FIGURE 4 is a fragmentary, side elevational view 3 taken on the lines4-4 of FIGURE 3 with parts broken away to show the pivoted catch memberwith a camshaped hook portion engaging the handle of the shutter. FIGURE5 is a fragmentary plan view taken on the lines '5-*5 of FIGURE 1showing the oven door latch mechanism in its un'latched position.

Description of the preferred embodiment Turning now to a considerationof the drawings and in particular to FIGURE 1 there is shown forillustrative purposes a free-standing electric range having a topcooking surface 11 with a plurality of surface heating elements '12, abaking oven 13 formed by a box-like oven liner 1'4- and a front-opening,drop-door 15. While the oven door of the present invention is shown asbeing installed on an electric oven, it will readily be apparent tothose skilled in this art that the invention is not limited to use withan electric oven. I may be used just as well with an oven heated by gasor perhaps other heat energy sources. It could also be used with abuilt-in oven or in fact any type of high temperature cavity. The ovencavity is supplied with two standard heating elements; namely, a lowerbaking element 16 and an upper broiling element 17 located adjacent thetop wall of the oven liner. There is also a mul'lion heater 24 whichencircles the front portion of the oven liner 14 and serves to replenishthe heat lost through and around the door during the heat cleaningoperation to obtain generally uniform wall temperatures throughout. Theback edge of the top cooking surface 11 is supplied with a backsplash 18which supports a control panel on which is mounted control components 19such as an oven selector switch, an oven thermostat, oven timer and thelike. The surface heating units 12 are controlled by multiple pushbuttonswitches 20 located in the two side arms of the cooktop. Preferably, theoven heating elements 16-, 17 and 24 and their control switches, an oventhermostat and oven timers will be arranged and operated as described inthe aforementioned Hurko patent to provide the normal cooking operationsas well as the high temperature oven cleaning operation. Positionedbeneath the oven 13 is a pull-out drawer 22 which is a storage drawerfor cooking utensils and the like. However, in the standard gas oventhis space is usually allotted to a separate broiler compartment.

As is best seen in FIGURE 2, the oven door 15 is of generally sheetmetal fabricated construction having three main elements; an outerdecorative door panel 26, an inner door liner 27 and a floating innerpanel 28 supported from the inner door liner 27. For purposes of thisinvention the two inner door members, the inner door liner 2'7 and thefloating inner panel 28, will be referred to as the inner door panel.The outer door panel 26 is of shallowpan shape in virtue of the factthat it has a slight, rearwardly turned peripheral flange 30. The innerdoor liner is also of shallow-pan shape, and it is of matingconstruction with the outer door panel 26 by virtue of the fact that ithas a front-turned peripheral flange 31 which telescopes Within theflange of the outer door panel 26. The inner door liner 27 includes agenerally rectangular, central, outward em'bossment 32 of such a size asto fit closely within the front opening of the oven liner, as is bestseen in FIGURES 1 and 2.

The floating door panel 28 is likewise of shallow-pan shape having afront-turned peripheral flange 34, and it covers an area that isslightly less than the area of the outer embossments 32 of the innerdoor liner 27. A high temperature gasket 35 of woven fiberglass or thelike is sandwiched under the periphery of the door panel 28 and fastenedto the inner door liner 27 by means of several fastening means widelyspaced around the periphery thereof. A more detailed explanation of thisfastening means and door structure may be found in the patent ofClarence Getman No. 3,189,020 entitled Oven Door with Floating InnerPanel, which is also assigned to the Gen- 4 eral Electric Company, theassignee of the present invention. 7

The oven door 15 is supplied with a stationary door handle 38 adjacentthe top portion thereof as is seen in FIGURE 1. The handle is fastenedto the door by screw members (not shown) which extend through the door.Thus the screws for mounting the handle 38 also serve as part of thefastening means for holding the inner door liner 27 to the outer doorpanel 26. Moreover, the oven door 15 is hinged to the range body alongthe bottom edge of the door by means of hinge arms (not shown), as isstandard in this art.

Looking at FIGURE 2, the present invention relates to a high temperaturetransparent window 45 formed in the oven door 15 and used by thehousewife for viewing the food while it is being cooked in the oven.This window is so constructed that it is protected by means of avertically movable shutter 46 which serves both as a radiation barrierand a visual barrier during a high temperature oven operation. The dooralso has an interlocking means shown at the top of FIGURE 3 forcooperation with an oven door latching system shown in FIGURE 5 so as topreclude the operation of the high temperature cycle unless the ovenwindow is first protected by the movable shutter as will be betterunderstood hereinafter.

A window opening is formed in each of the three door elements; namely,the outer door panel 26, the inner door liner 27, and the floating innerpanel 28. Thus, there is a window opening 47 in the outer door panel 26,a window opening 48 in the inner door liner 27 and finally a matchingwindow opening 49 in the floating inner panel 28. It is well to providea plurality of high temperature transparent glass panes in the windowopenings so as to improve the thermal insulating properties of thewindow and retard heat transfer to the exterior of the range. Moreover,it is well to provide for the sealing of the window so as to prevent theescape of odors, vapors as well as convection currents of hot air. It isparticularly important to prevent the condensation of oven vapors 0n theinner surfaces of the glass panes which would otherwise tend to soil theglass and obscure viewing into the oven cavity.

As seen in FIGURE 2, it will be recognized that there are three glasspanes 51, 52 and 53. The two frontmost panes 51 and 52 are separated bya continuous spacer frame 54, and they are held together by an outerframe 55 of U-shaped transparent cross-section which fits around theperiphery of the two panes to form a sealed window unit 58. A decorativetrim frame 57 extends around the periphery of the front edge of theoutermost glass pane 51, and is held by studs (not shown) to the outerdoor panel 26. This window unit sub-assembly 58 is shown as beingfastened to the back side of the outer door panel 26 by means of supportflanges 60 and 61 by means of screw fasteners 62.

The third glass pane 53 is shown in FIGURE 2 as being fastened over thewindow openings 48, 49 from the inner side thereof by means of fasteningscrews and clip members (not shown) along the top and bottom edges ofthe third pane 53. Moreover, there is a decorative trim frame 66assembled around the peripheral edge of the glass pane 53 so as to maskthe peripheral edge of the glass pane from view. This trim frame 66telescopes into the window opening 49 of the floating inner panel 28. Asuitable sealing gasket 68 is sandwiched between the glass pane 53 andthe inner door liner, again to seal the glass against the escape ofgases and vapors around the edges thereof.

Notice that thermal insulation 70 of fiberglass or the likesubstantially fills the floating inner panel 28. A second layer ofinsulation 71 is located between the outer door panel 26 and the innerdoor line-r 27, but it does not completely fill this cavity. There is afront air channel 72 formed between the inner surface of the outer doorpanel 26 and an insulation guard 73 which holds the insulation 71 inplace. Suitable air inlet openings (not shown) are formed in the bottomedge of the door 15 to permit room air to rise through the air channel.Moreover, the top-edge of the door is provided with suitable air outletopenings (not shown). A second insulation guard 75 confines the otherside of the insulation 71 so that the raised embossment 32 issubstantially hollow.

The hollow raised embossment 32 includes the spacing between the secondwindow pane 52 and the third window pane 53. The purpose of this hollowchamber is to accommodate a reflective shutter 46 which is shown in theraised position in FIGURE 3, but which is capable of being retractedinto the lower portion of the door so as to be completely out of viewand enable the housewife to see into the oven cavity 13. This shutter 46is of generally rectangular configuration and may be formed of aluminumsheet metal. The shutter 46 is supported and guided on a track systemcomprising a pair of vertical rails 77 of generally Z-shape intransverse, cross-sectional view as it best seen in FIGURE 2. Each rail77 is positioned inboard of the related vertical side of the shutter 46.Adjacent the upper and lower extremity of each vertical side of theshutter 46 is fastened a slide member 79 which is preferably ofnon-metallic material that is impregnated with graphite such as is soldunder the tradename Graphitar that is sold by the US. Graphite Companyof Saginaw, Michigan. Such a material has a characteristic lubricitywhich is not effected by high temperatures in the vicinity of 900 F. inthat it does not lose its low friction characteristic. This cooperationbetween the four slide members 79 and the two rails 77 of the tracksystem gives positive location of .the shutter and prevents any jammingaction that might be caused by thermal expansion of the shutter 46.

The shutter 46 is a symmetrical member and as seen in FIGURE 3 the uppercorners of the shutter are each provided with an outwardly extendinghandle 81. Looking at FIGURE 1 the side walls of the outer emboss-ments32 are provided with a long, narrow, vertical slot 83 through which thehandle 81 extends. Of course, the purpose of the handle is to enable thehousewife to grasp the shutter 46 and raise or lower it as is needed.

It is necessary to provide means for supporting the shutter 46 in itsraised position, and this invention contemplates the use of a gravityactuated catch member 85 as is best seen in FIGURES 3 and 4. This catch85 is a pivotal member that is pivoted about its top end by -a pivot pin87 that is supported in the side wall of the raised embossment 32slightly above the top end of the slot '83 as is best seen in FIGURE 4.The lower end of the catch 85 is provided with a cam-shaped hook 88which faces toward the front surface of the door 15. The cam surf-ace ismarked 89 and the hook has a lip 90 which is adapted to engage behindthe handle 81 and prevent inadvertent removal of the catch from thehandle. It will be understood that the handles 81 cannot be reachedunless the oven door 15 is first opened. Thus with the door 15 in eithera partially open or fully open position it is clear that the hookportion 88 is located beside the slot 83. Hence when the shutter 46 isto be raised by engaging and lifting the handles 81, the handles willstrike .the cam surface 89 and the catch 85 will be deflected out of theway until the handles move above the hook portion 88 at which time thecatches are moved by gravity back beneath the handles and areautomatically engaged thereby.

Means must be provided for releasing the catch member so that theshutter 46 may be lowered upon the completion of the self-cleaning ovencycle and after the door is opened. Such a release means is shown inFIGURE 4 as a combination of an arcuate slot 93 that is generallyconcentric with the pivot pin 87 of the catch, and a tab 95 formed as anintegral part of the catch near its pivotal axis. The tab extends outthrough the slot 93 to be accessible on the inner face of the oven door15. Thus to move the shutter 46 to its retracted position, the housewifewould open the door and first lift upwardly on the 6 handles '81 andsimultaneously lift the tabs of the catch members thereby pivoting thecatches out of engagement with the handles so the handles can be lowereduntil the shutter reaches its completely retracted position in the doorbeneath the window.

FIGURE 5 merely shows a door latch mechanism which is adapted to bebuilt into the range body above the front of the oven liner 14 so thatthe oven door may be locked and may not be opened during the hightemperature heat cleaning operation. The specific door latchingmechanism is fully disclosed in the patent to Clarence Getman No.3,189,375 which is assigned to the same assignee as is the presentinvention. The mechanism includes a handle 102 which extends through anelongated, horizontal slot 103 in the front of the range body, forexample, beneath the cooktop 11 as is best seen in FIGURE 1. A completedescription of this door latch mechanism is not deemed necessary heresince it does not form part of the present invention. It does, however,include a latching bolt 108 pivoted to a mounting bracket 109 by meansof pin and slot connections which are shown in dotted lines therein.When the door latch handle 102 is moved from left to right for latchingthe door, the latching bolt 108 is caused to swing in a horizontal planeand reach out of the range body through the elongated slot 103 forengaging in a keeper slot 112 that is formed in the inner surface of theinner door liner 27 as is best seen in FIGURE 3.

As is taught in the before-mentioned Baughman et al. Patent No.3,311,106, the oven door 15 is provided with a mechanical door latchinterlocking system to insure that the door latch 100 cannot be closedunless the movable shutter 46 is first raised to its window blockingposition as shown in FIGURE 3. One side of the upper edge of the shutter46 is provided with a finger member 115 which is capable of engaging apivoted interlocking member 116 which is normally biased by spring means117 into a position to cover or to close the keeper slot 112 in thedoor. If the shutter is not raised, this interlocking member 116 fillsthe keeper slot and prevents the pivoted bolt member 108 of the doorlatching mechanism from entering the keeper slot and hence the doorlatch handle 102 cannot be moved to its closed position. There aresuitable switch means (not shown) which must be closed by the doorlatching mechanism in the closed position before the heat cleaningcircuit can be established, and the heat cleaning cycle initiated.

Modifications of this invention will occur to those skilled in this art,therefore, it is to be understood that this invention is not limited tothe particular embodiments disclosed but that it is intended to coverall modifications which are within the true spirit and scope of thisinvention as claimed.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In an oven door having a window formed therein, said door comprisingan outer door panel with a first window opening, at least onetransparent pane sealed over the said first window opening, an innerdoor panel with a second window opening, at least one transparent panesealed over the said second window opening, and fastening means forattaching the inner and outer door panels together, and a shutterpositioned within the door and movable between a first positionretracted within the door structure and a second position blocking theview through the window, the shutter having handle portions formed onopposite sides thereof, and slots formed on the inner door panel forreceiving the handle portions therethrough for accessibility when thedoor is open, and at least one pivoted catch member positioned withinthe door and having a cam-shaped hook portion, said catch member beingbiased by gravity under an adjacent handle portion when the shutterreaches its raised blocking position for holding the shutter in place,and manual releasing means for withdrawing the catch from the shutter sothe shutter may be lowered to its said first retracted position.

2. In an oven door having a window formed therein, said door comprisingan outer door panel with a first window opening, at least onetransparent pane sealed over the first window opening, an inner doorpanel with a second Window opening, at least one transparent pane sealedover the second window opening, and fastening means for attaching theinner and outer door panels together, and a shutter positioned withinthe door and movable between a retracted position in the lower portionof the door structure and a raised position blocking the view throughthe window, track means within the door on which the shutter issupported and guided in its movement, the shutter having handles at thetop corners thereof, and slots formed on the inner door panel forreceiving the respective handles therethrough, and at least one catchmember positioned within the door and near the top of the said slot,said catch having a camshaped hook portion which is biased to move underan adjacent handle when the door is open and the shutter is manuallyraised to its blocking position for supporting the shutter in place, andmanual release means for disengaging the catch from the shutter so theshutter may be moved to its retracted position.

3. In an oven door as recited in claim 2 wherein the catch member is apivotal member with its pivot at one end thereof adjacent the top edgeof the door, and the said cam-shaped hook portion is at the lower end ofthe member and facing toward the front panel of the door, and a smallopening in the inner door panel, the said manual release meanscomprising a tab on the catch member which extends outwardly through thesmall opening.

4. In an oven door having a window formed therein, said door comprisingan outer door panel with a first window opening, at least onetransparent pane sealed over the said first window opening, an innerdoor panel with a second window opening, at least one transparent panesealed over the said second window opening, and fastening means forattaching the inner and outer door panels together, and a shutterpositioned within the door and movable between a first positionretracted within the door structure and a second position blocking theview through the window, the shutter having handle portions formed onopposite sides thereof and accessible when the door is open, and atleast one movable catch member positioned on the door and biased intohandle engaging position when the shutter reaches its raised blockingposition for holding the shutter in place, and manual releasing meansfor withdrawing the catch from the shutter so the shutter may be loweredto its said first retracted position.

References Cited UNITED STATES PATENTS 2,926,658 3/1960 Ligon 126-2003,311,106 3/1967 Baughman et a1. l26200 3,396,717 8/1968 Winkler et al12 6-200 KENNETH W. SPRAGUE, Primary Examiner.

